Freedom Tower is dressed in red, white and blue in anticipation for President Obama’s visit today. (William C Lopez)

Mr. President, welcome to the new World Trade Center. Don’t call it Ground Zero — that name belongs in the briny deep with Osama bin Laden’s corpse. Here, towers are rising.

It’s hard to believe after a near-decade of delays, false starts and chaotic “planning,” but “Pataki’s Pit” is at the heart of a revolution sweeping all of Downtown. Come this fall’s 10th anniversary of the attacks, the years of despairing over lack of progress will seem a distant memory.

The renaissance comes both within and beyond the 16 acres of the old WTC site. To stand at Church and Vesey streets is to witness a new Downtown being born.

Where to start? The memo rial should be largely real ized by this Sept. 11 (although how much of it will be open remains to be seen).

An underground museum and seven acres of trees and waterfalls don’t stir you? The sight of two of the world’s greatest new office towers — 1 and 4 World Trade Center — racing for the sky could do the trick.

Across the street from them, 7 WTC is nearly fully leased at the highest rents ever paid in Lower Manhattan; law firm WilmerHale, moving from Midtown, is the newest tenant.

To its immediate west in Battery Park City stands Goldman Sachs’ new headquarters. A short stroll east is the 76-story, Frank Gehry-designed 8 Spruce St. — the city’s tallest apartment tower, emblematic of Lower Manhattan’s status as New York’s fastest-growing residential neighborhood.

Even behind-schedule, super fluous projects launched in the wake of 9/11 lift the heart as they finally take tangible form. The MTA’s Fulton Street Transit Center and a new Fiterman Hall are vastly preferable to the empty lots and rubble that preceded them.

Similarly, the Santiago Calatrava-designed World Trade Center Transportation Hub — essentially a gargantuan PATH terminal — is too late to turn back. Launched by governors and Port Authority officials long out of power, the tortured project is finally taking bids on above-ground steel.

Most portentous are the pair of architecturally distinc tive commercial edifices that have emerged out of a decade’s bureaucratic and political fog. They are half the number that should be under construction. But they are two more than we had any expectation of seeing not very long ago.

And despite having less than half the square footage of the old WTC, they count for more, thanks to much greater efficiency of today’s floor plates and technology.

They’ll also make the memorial — at first so bleak it needed to be softened with 500 trees — better than it is. The memorial’s pools and subterranean artifacts dwell on bin Laden’s work, with little hint that 9/11 was defined by selflessness and heroism on a mass scale commensurate with the tragedy — but the bold verticality of 1 and 4 WTC speak to the site’s future life.

More important, the towers ensure the city’s preeminent global stature as the center of finance and commerce. The iconic 1 WTC will almost certainly be the new home of Conde Nast; a signed lease will exert a gravitational pull on other companies to move to the WTC and catalyze construction of 2 WTC and 3 WTC, now on hiatus until the economy improves.

That both 1 and 4 WTC might take time to be fully rented is immaterial to anyone with a grasp of history. A New York Times columnist recently dismissed the towers as real-estate follies that oughtn’t be built because of tepid demand. With a commercial vacancy rate around 11 percent, why should we add 5 million square feet more? Even The Wall Street Journal this week joined the braying peanut gallery.

If that logic had ruled, we’d never have had the Twin Towers, which took decades to fill with private-sector tenants — nor the beloved landmark once known as the Empty State Building. The city’s need for state-of-the-art office space to supplant its obsolescent inventory is beyond argument, except to the wilfully ignorant.

The new towers already make powerful skyline statements. The David Childs-designed 1 WTC, built by the PA in partnership with the Durst Organization, has reached two-thirds of its 102-story height. Enough of the curtain wall now wraps the shaft’s midsection to allow one nearly to visualize it whole. The glass reflects its surroundings not like a mirror, but as a filter softly diffusing neighbors such as the Woolworth Building as in an Impressionist painting.

Meanwhile, enough steel for Larry Silverstein’s 4 WTC, designed by Fumihiko Maki, is in place to hint at its eventual mass and 64-story height. More conventionally shaped than 1 WTC, the tower will possess its own austere beauty.

So much has come into focus, it’s too easy to forget the morass of 2002-2007 — the time wasted by Gov. George Pataki’s design competition and Daniel Libeskind’s disastrous “master plan” and all the endless turf wars. It took years of sustained outrage over the lack of progress — expressed first and most forcefully in the pages of The Post — to break the logjam.

Many have said the public was led to expect too much, too soon, after 9/11 — but it was only public and media outrage that finally moved elected officials and developers to action.

The new World Trade Center still has detractors — from developers jealous not to be involved there, to defeatists opposed to any new building, to Twin Towers fanatics for whom only restoration of the banal hulks would do.

For everyone else, there is cause to celebrate. This Sept. 11, on the 10th anniversary of the attacks, mourning for the nearly 2,800 who perished will be leavened by evidence of sweeping rebirth.

No reconstruction can undo bin Laden’s evil or the sorrow it brought to so many. But go downtown, look to the sky and believe. scuozzo@nypost.com